DOHA, Qatar — Venus Williams advanced to the final of the Sony Ericsson Championships with a 6-2, 2-6, 6-3 win today over top-ranked Jelena Jankovic.

Williams will face Vera Zvonareva, who defeated Olympic champion Elena Dementieva 7-6 (7), 3-6, 6-3 in the other semifinal at the WTA Tour's season-ending event.

Williams saved five break points before winning a grueling service game in the third set to go up 4-2. That game also featured a 26-stroke rally, the longest of match. She went on to clinch the victory with a backhand crosscourt winner on her first match point.

The American dominated in the first set, but made more errors in the second as Jankovic dictated play with her aggression. She broke Williams to lead 4-2, and closed out the set with relative ease.

The eighth-ranked Williams improved her record against Jankovic to 4-5.

The ninth-ranked Zvonareva, the lowest-ranked player in the eight-woman field, improved to 2-4 against Dementieva and avenged her semifinal loss at the Beijing Olympics.

"I knew I had to start to play good every single game," Zvonareva said.

Zvonareva frustrated Dementieva with solid groundstrokes in the final set and capitalized on a string of errors by her opponent to win the last game at love.

Zvonareva recovered from a 1-4 deficit in the first set. In the tiebreaker, Dementieva rallied from 5-1 down and lost a set point before hitting a backhand wide on Zvonareva's second set point. The Russians broke each other four times in the first set.

Dementieva also had a 4-1 lead in the second set, and this time held it to even the match. She called Zvonareva a strong competitor.

"You have to put pressure all the time," Dementieva said.